37 lines
887 B
Go
37 lines
887 B
Go
//go:build !windows
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// Package processalive probes whether an operating-system process id still
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// maps to a live process.
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package processalive
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import (
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"bytes"
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"errors"
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"os/exec"
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"strconv"
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"syscall"
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)
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// Alive reports whether pid maps to a running process. EPERM counts as alive:
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// the process exists even if the current user cannot signal it. Zombies are
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// treated as not alive because the executable has already exited; only its
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// parent has not reaped the process table entry yet.
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func Alive(pid int) bool {
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if pid <= 0 {
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return false
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}
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err := syscall.Kill(pid, 0)
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if err != nil && !errors.Is(err, syscall.EPERM) {
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return false
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}
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return !isZombie(pid)
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}
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func isZombie(pid int) bool {
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out, err := exec.Command("ps", "-o", "stat=", "-p", strconv.Itoa(pid)).Output()
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if err != nil {
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return false
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}
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return bytes.HasPrefix(bytes.TrimSpace(out), []byte("Z"))
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}
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